madbeanpedals::forum

Projects => General Questions => Topic started by: Wellu on June 03, 2016, 05:43:13 PM

Title: Wondering if anyone might recognize what compressor this is?
Post by: Wellu on June 03, 2016, 05:43:13 PM
I just got it today on the side of a deal. It is old and in bad shape. i am going to restore it, just don't know what compressor it is.

It has 3 potentiometers, 100K A, 500K C and A504.
Title: Re: Wondering if anyone might recognize what compressor this is?
Post by: Drew Hallenbeck on June 03, 2016, 06:02:55 PM
With the CA3080 in there, it's definitely some variant of an OTA (operational transconductance amplifier) compressor. Ross, Keely, Dynacomp, etc.....
There are quite a few versions of compressors that have been built around that particular chip over the years.
Sorry, I know it's a pretty vague answer. Maybe someone else here will recognize something that will help pin it down a bit better.
Title: Re: Wondering if anyone might recognize what compressor this is?
Post by: Wellu on June 03, 2016, 06:18:55 PM
Thanks for your answer! My question is not exactly fair, just wanted to see if someone would recognize some particular element of the comp.

Title: Re: Wondering if anyone might recognize what compressor this is?
Post by: Govmnt_Lacky on June 03, 2016, 07:23:44 PM
Will be difficult without a schematic. Possibly even a trace side picture but that would just lead to someone building a schematic anyways to determine the circuit.
Title: Re: Wondering if anyone might recognize what compressor this is?
Post by: thesmokingman on June 03, 2016, 07:35:57 PM
guessing by the general construction and capacitor type its a very old cp9 ... again, guessing
Title: Re: Wondering if anyone might recognize what compressor this is?
Post by: Wellu on June 03, 2016, 08:28:44 PM
I agree, it really looks like an old Ibanez pcb. I tried to look for this pedal and i saw that a lot of cp9's are made with lm13600.

Maybe in the really old ones they used CA3080 design? I have no idea.. thanks everyone!
Title: Re: Wondering if anyone might recognize what compressor this is?
Post by: Martan on June 04, 2016, 01:06:09 AM
Ive seen those yellow caps and straight outboard wiring layouts in Maxon pedals
Title: Re: Wondering if anyone might recognize what compressor this is?
Post by: gordo on June 04, 2016, 02:08:12 AM
The pads at one end look like boss.
Title: Re: Wondering if anyone might recognize what compressor this is?
Post by: midwayfair on June 04, 2016, 03:21:25 AM
This is the closest I can come up with:

http://www.dirk-hendrik.com/ibanez_cp835.pdf

Assuming the third pot with the weird value you said is the trimpot. But it's 11 transistors and a metal can 3080. I can say it's definitely nothing else in this thread and that it can't be Boss (would be inline ICs most likely and they never made a 3080 comp), that all versions of the Ibanez variant used the 13700, and that no Dynacomp variant would have 10 transistors.

There's a very vague chance it's something rare by EHX. They did make a 3080 compressor at some point I think, but I don't remember what it's called. Paging Scruffie?
Title: Re: Wondering if anyone might recognize what compressor this is?
Post by: JC103 on June 04, 2016, 05:48:04 AM
Could it possibly be a Boss CS-1?
Title: Re: Wondering if anyone might recognize what compressor this is?
Post by: Wellu on June 04, 2016, 07:17:45 AM
I asked a local guy and he gave me an interesting answer. "Since the Dynacomp and Ross compressor have been copied dozens and dozens of times since the mid 70's it is fairly impossible to find out exactly what compressor it is, given the CA3080 and the position of the trimpot it definitely has it's origins in the Dynacomp, but not exactly, because it has 3 pots. 100K A is volume, 500K C is comp, and the last one A504 must be attack or tone. Otherwise it would leave too many options to choose from, but given that this circuit has been "floating" inside the enclosure it narrows it down a bit, because massively produced brands like Aria and such had the switches/jack soldered on the pcb to reduce the workload". So in his opinion the circuit looks like a Locobox, but their catalog does not have a 3 knob compressor, so it leaves us with Guyatone PS-003 (if the third knob acts as a tone) http://www.effectsdatabase.com/model/guyatone/ps00x/ps003 or Frontline 178828 (if the third knob is attack) http://www.effectsdatabase.com/model/frontline/series3/178828.
Title: Re: Wondering if anyone might recognize what compressor this is?
Post by: Scruffie on June 04, 2016, 10:25:13 AM
Quote from: midwayfair on June 04, 2016, 03:21:25 AM
This is the closest I can come up with:

http://www.dirk-hendrik.com/ibanez_cp835.pdf

Assuming the third pot with the weird value you said is the trimpot. But it's 11 transistors and a metal can 3080. I can say it's definitely nothing else in this thread and that it can't be Boss (would be inline ICs most likely and they never made a 3080 comp), that all versions of the Ibanez variant used the 13700, and that no Dynacomp variant would have 10 transistors.

There's a very vague chance it's something rare by EHX. They did make a 3080 compressor at some point I think, but I don't remember what it's called. Paging Scruffie?
The Low Frequency Compressor & Black Finger, it's neither of those, the PCB looks like it might be something Guyatone related.
Title: Re: Wondering if anyone might recognize what compressor this is?
Post by: Scruffie on June 04, 2016, 10:45:40 AM
Whoops, just saw you already came to the conclusion it's Guyatone related.

Anyway, i'd say this is it;
(https://images.ttcdn.co/media/i/product/4802-04b3758f896b49d3bd1e76eed55abc22.jpeg?size=2000&crop=0,0,3456,2304)
Title: Re: Wondering if anyone might recognize what compressor this is?
Post by: Wellu on June 04, 2016, 10:56:16 AM
Hey.

It is almost exactly the same. Maybe a different model? But Guyatone, no doubt. Thanks!